Exemplo n.º 1
0
static basic_block
construct_init_block (void)
{
  basic_block init_block, first_block;
  edge e = NULL;
  int flags;

  /* Multiple entry points not supported yet.  */
  gcc_assert (EDGE_COUNT (ENTRY_BLOCK_PTR->succs) == 1);

  e = EDGE_SUCC (ENTRY_BLOCK_PTR, 0);

  /* When entry edge points to first basic block, we don't need jump,
     otherwise we have to jump into proper target.  */
  if (e && e->dest != ENTRY_BLOCK_PTR->next_bb)
    {
      tree label = tree_block_label (e->dest);

      emit_jump (label_rtx (label));
      flags = 0;
    }
  else
    flags = EDGE_FALLTHRU;

  init_block = create_basic_block (NEXT_INSN (get_insns ()),
				   get_last_insn (),
				   ENTRY_BLOCK_PTR);
  init_block->frequency = ENTRY_BLOCK_PTR->frequency;
  init_block->count = ENTRY_BLOCK_PTR->count;
  if (e)
    {
      first_block = e->dest;
      redirect_edge_succ (e, init_block);
      e = make_edge (init_block, first_block, flags);
    }
  else
    e = make_edge (init_block, EXIT_BLOCK_PTR, EDGE_FALLTHRU);
  e->probability = REG_BR_PROB_BASE;
  e->count = ENTRY_BLOCK_PTR->count;

  update_bb_for_insn (init_block);
  return init_block;
}
Exemplo n.º 2
0
void
genrtl_goto_stmt (tree destination)
{
    if (TREE_CODE (destination) == IDENTIFIER_NODE)
        abort ();

    /* We warn about unused labels with -Wunused.  That means we have to
       mark the used labels as used.  */
    if (TREE_CODE (destination) == LABEL_DECL)
        TREE_USED (destination) = 1;

    emit_line_note (input_location);

    if (TREE_CODE (destination) == LABEL_DECL)
    {
        label_rtx (destination);
        expand_goto (destination);
    }
    else
        expand_computed_goto (destination);
}
Exemplo n.º 3
0
static basic_block
expand_gimple_cond_expr (basic_block bb, tree stmt)
{
  basic_block new_bb, dest;
  edge new_edge;
  edge true_edge;
  edge false_edge;
  tree pred = COND_EXPR_COND (stmt);
  tree then_exp = COND_EXPR_THEN (stmt);
  tree else_exp = COND_EXPR_ELSE (stmt);
  rtx last2, last;

  last2 = last = get_last_insn ();

  extract_true_false_edges_from_block (bb, &true_edge, &false_edge);
  if (EXPR_LOCUS (stmt))
    {
      emit_line_note (*(EXPR_LOCUS (stmt)));
      record_block_change (TREE_BLOCK (stmt));
    }

  /* These flags have no purpose in RTL land.  */
  true_edge->flags &= ~EDGE_TRUE_VALUE;
  false_edge->flags &= ~EDGE_FALSE_VALUE;

  /* We can either have a pure conditional jump with one fallthru edge or
     two-way jump that needs to be decomposed into two basic blocks.  */
  if (TREE_CODE (then_exp) == GOTO_EXPR && IS_EMPTY_STMT (else_exp))
    {
      jumpif (pred, label_rtx (GOTO_DESTINATION (then_exp)));
      add_reg_br_prob_note (dump_file, last, true_edge->probability);
      maybe_dump_rtl_for_tree_stmt (stmt, last);
      if (EXPR_LOCUS (then_exp))
	emit_line_note (*(EXPR_LOCUS (then_exp)));
      return NULL;
    }
  if (TREE_CODE (else_exp) == GOTO_EXPR && IS_EMPTY_STMT (then_exp))
    {
      jumpifnot (pred, label_rtx (GOTO_DESTINATION (else_exp)));
      add_reg_br_prob_note (dump_file, last, false_edge->probability);
      maybe_dump_rtl_for_tree_stmt (stmt, last);
      if (EXPR_LOCUS (else_exp))
	emit_line_note (*(EXPR_LOCUS (else_exp)));
      return NULL;
    }
  gcc_assert (TREE_CODE (then_exp) == GOTO_EXPR
	      && TREE_CODE (else_exp) == GOTO_EXPR);

  jumpif (pred, label_rtx (GOTO_DESTINATION (then_exp)));
  add_reg_br_prob_note (dump_file, last, true_edge->probability);
  last = get_last_insn ();
  expand_expr (else_exp, const0_rtx, VOIDmode, 0);

  BB_END (bb) = last;
  if (BARRIER_P (BB_END (bb)))
    BB_END (bb) = PREV_INSN (BB_END (bb));
  update_bb_for_insn (bb);

  new_bb = create_basic_block (NEXT_INSN (last), get_last_insn (), bb);
  dest = false_edge->dest;
  redirect_edge_succ (false_edge, new_bb);
  false_edge->flags |= EDGE_FALLTHRU;
  new_bb->count = false_edge->count;
  new_bb->frequency = EDGE_FREQUENCY (false_edge);
  new_edge = make_edge (new_bb, dest, 0);
  new_edge->probability = REG_BR_PROB_BASE;
  new_edge->count = new_bb->count;
  if (BARRIER_P (BB_END (new_bb)))
    BB_END (new_bb) = PREV_INSN (BB_END (new_bb));
  update_bb_for_insn (new_bb);

  maybe_dump_rtl_for_tree_stmt (stmt, last2);
  
  if (EXPR_LOCUS (else_exp))
    emit_line_note (*(EXPR_LOCUS (else_exp)));

  return new_bb;
}